Swift – 如何获取按钮值,何时按下？

我已经尝试过用给定代码打印4 * 4矩阵 –

func creation_of_btn()
{
var x_axis:CGFloat = 50.0
var y_axis:CGFloat = 50.0

for x in 1...4
{
  for y in  1...5
  {
       let btn_creat = UIButton.buttonWithType(UIButtonType.Custom) as UIButton!
       btn_creat.frame = CGRectMake(x_axis,y_axis,100,100)
       x_axis += 110.0
       btn_creat.backgroundColor = UIColor .redColor()

       btn_creat.font = UIFont .boldSystemFontOfSize(50)

       var myString = String(self.rand_creation(1,second: 9))
       btn_creat .setTitle(myString,forState: UIControlState.Normal)
       btn_creat.addTarget(self,action: "btnAction:",forControlEvents: UIControlEvents.TouchUpInside)
       self.view.addSubview(btn_creat)
   }

   x_axis = 50.0
   y_axis += 110.0
}
}

按下按钮时,代码为 –

func btnAction (sender:UIButton!)
{
   println("pressed")
}

通过上面的代码,我得到以下输出 –

现在,当我按下按钮1时,我想打印按钮值,即1.